The present invention relates to improved solutions for conveying dynamo-electric machine core components (e.g., armatures or stators for electric motors, generators, or alternators) between different processing machines of a manufacturing assembly line.
In a typical manufacturing assembly line, processing machines for processing dynamo-electric core subassemblies (i.e., components at various stages of a manufacturing process) are placed at workstations along the assembly line. Core subassemblies are often transported along the assembly line from one machine to another by a conveyor apparatus while mounted on pallets. Particular disposition of processing machines along an assembly line, the transport routes by which the pallets reach the machines, and the sequences with which the pallets reach the machines have been described, for example, in Santandrea et al. U.S. Pat. No. 4,984,353, and Becherucci et al. U.S. patent application Ser. No. 09/409,038, which are hereby incorporated by reference herein in their entireties.
Santandrea et al. and Becherucci et al. disclose systems in which subassemblies that have been processed by a machine at a work station are transferred to pallets. The pallets are then transported along the conveyor apparatus to another workstation in the assembly line for processing according to the next step of the manufacturing process. Once the pallets reach the other work station, the subassemblies are transferred from the pallets into a machine at the other workstation for the next step of processing. This process of transferring the subassemblies in and out of machines and of moving the subassemblies from one workstation to another is repeated for each of the various steps of the manufacturing process. The repeated transfers back and forth between pallets and machines, and the repeated movements of pallets between workstations, both contribute to overall manufacturing processing time and expense.
Consideration is now being given to ways of enhancing workstation configurations and subassembly transport mechanisms to improve the overall efficiency of dynamo-electric core manufacturing systems.
In accordance with the principles of the invention, an assembly line workstation is configured to include a sequence of step-processing machines or units for concurrently processing dynamo-electric machine core subassemblies that are at different stages of manufacture. The units are placed in sequence to perform process steps in the same order as the sequence of steps in the manufacturing process.
The workstation includes a row of receiving structures designed to hold subassemblies in position for processing by the units. The receiving structures may, for example, be spaced-apart seats designed to support extreme-portions of the subassemblies. The row may include input and output receiving structures that serve as waiting locations for input and output subassemblies. The row of receiving structures is supported on beam structures running across the length of the workstation. These beam structures may, for example, be a pair of beams that are continuous over the length of the row of receiving structures.
A movable transferor moves subassemblies forward along the row of receiving structures. The transferor is designed to simultaneously advance a group of subassemblies. The transferor may be a movable central beam with a row of holders aligned with the row of receiving structures. The holders are shaped to lift the subassemblies out of the receiving structures and to hold the subassemblies while moving them forward.
Suitable mechanical linkages impart controlled motion to the central beam. The controlled motion is designed to move the holders along paths to lift the subassemblies from the row of receiving structures and redeposit the subassemblies in the adjoining receiving structures. The paths may, for example, be rectangular paths starting from positions underneath the receiving structures. Traveling along the rectangular paths, the holders first move vertically upwards lifting subassemblies from the receiving structures, and then move horizontally forward to be above the adjoining receiving structures. Vertically downward motion redeposits the subassemblies in the adjoining receiving structures. Finally, backward horizontal motion returns the holders to their starting positions.
In an embodiment of the present invention the processing units and the receiving structures may be placed, for example, above an assembly line floor, on a table top. The movable central beam operates above the table top between the row of receiving structures. Mechanical linkages that impart motion to the central beam may be placed underneath the table top. The table top, for example, supported on legs, may be suitably designed to reduce the effect of floor vibrations and provide mechanical stability for processing operations.
Since the subassemblies are moved forward through the workstation together in a group, every time a fully processed subassembly is moved to the output receiving structure, the input receiving structure becomes vacant and available to receive new input to the workstation. An input subassembly may be loaded into the workstation (i.e., placed in the vacant input receiving structure) at the same time as the output subassembly is unloaded from the workstation. The loading and unloading operations may occur even as other subassemblies are being processed by the sequence of units in the workstation.